half-way to a true gate-fold, in fact: take a sheet of card three times the width of a normal single lp sleeve, fold it twice, one-third of the way in from right & left-hand edges, and glue narrow top & bottom flaps along the right-hand third to top and bottom edges of the middle third, to form the pouch to hold the lp in its paper insleeve.
makes for a rather readily-creased, flappy front. (& "pouch" is the word; last time i remember seeing this style of sleeve was on the atv/pye kinks' lp, arthur, or the decline and fall of the british empire, whose inside illo was of a ginormous kangaroo - and the lp slotted neatly into the card sleeve's - and the kangaroo's - pouch°.)
(° - *vbg*. sometimes, even pye records got it right...)